In my opinion, a mat foundation is nothing more than a slab with a reversed load. As a first approximation, you could try and design it as a slab with drop panels. You would have to know the pressure distribution below the foundation, which requires some calculation to obtain, but that is...
I have used RAM Advanse for this problem, modeling the slabs using shell elements. Now, this has its own limitations, because it is difficult to reduce the stiffness of the shells for cracked section properties of the slab(as required for drift calcs and PDelta analysis). The only way is by...
I can´t see your model, but probably the vertical element is just acting as a tie that "shares" the point load between the top and bottom chords. If there are no diagonals forming a triangle, it may happen. It may also have to do with the relative stiffness of the top and bottom chords. Are...
If I had to do this, I would not connect the beams with thru the web bolts. If you really need both beams for strenght and the load is not symmetrical you will have a problem, because I´m not so convinced that they will share the load. As has been stated above, it depends on many things.
I...
I agree with DaveAtkins in that the column will only attract as much moment as it can accept. However, you may end up with a brittle shear failure before the hinge forms, because the slab still has to resist a part of the unbalanced moment by shear mechanism. Additionally, the formation of...
A good chunk of the unbalanced moment has to be resisted by shear capacity in the supports. In my opinion, this has very little to do with how much flexural capacity you have or how much moment redistribution you are allowed by code to use.
I don't think you can neglect it. I would not...
I agree with Dave and jike for compression piles. No fancy design there. Only design as completely braced unreinforced section. I usually add some reinforcing steel in the upper 3 meters (about 0.5%) even if not required.
Calculated uplift and/or moment are a different ball game.
I believe you can´t do what you want in ADAPT PT. There is a way to change the datum line of the section (changing Rh parameter), but not the height of the flange with respect to the beam) Do you really need to be able to model it as an inverted L? With not as a rectangular beam?
Would the tank configuration and use allow you to use mid-height struts between walls? (Like what you would do to brace a deep excavation, but permanently).....
Is the slab part of the continuity, or is only the steel beam connected with moment connections, while the slab is disconnected to the support and only composite to the beam at this point?
In my humble opinion, I would disregard any effect (with the exception of the already noted shared deflection between the upper and lower beam). It will be very hard to apply a torque through the kind of connection you have described , even if off the center of the beam. For a torque to exist...
My $0.02:
First a general comment: I believe that even tough the short columns where extended, most of the dead load has already been applied to the original foundations and the only beneficial effect is in better distribution of superimposed dead and live loads. This will of course depend on...
Is it effectively a drop panel as defined by ACI 318, or a column capital only required for shear considerations?
For drop panels you need to add it in case there are flexural stresses to handle. For example, could there be positive moments at supports due to seismic loads?. In Panama it is...
I don´t know about STAAD, but RAM Advanse (Also a Bentley product) lets you input if you want the nodes of program generated elements between two restrainsts to have the same restraint or none at all. This is very usefull in the situation described, because you only have to define a very large...
Thanks for the help. I was already trying to design a jointless pool. Any more opinions will be greatly appreciated.
What do you do in construction joints, waterstops?
I´m involved in the structural design of a fairly large swimming pool for a hotel facility. It is not a rectangular pool, but a very irregular one in plan.
The structural design is straightforward enough, however, I´d like some assistance specially in the detailing part:
1. Spacing, type and...
I would assume that the precast pannels stop a certain distance short of the column. Is it noticeable from the bottom of the slab? If so, perform 2 punching shear calculations:
1. at the required distance by code (typically d/2 by ACI) from the face of the column using the full d;
2. at the...